Self‐Assembled Zinc Supraparticles as Sustainable Fertilizer Platforms for Controlled Nutrient Release with Reduced Zinc Leaching in Soil

ABSTRACT The intensification of agriculture and the growing demand for food have driven the need for innovative technologies to improve the efficiency of agrochemicals. Nanoparticulate systems enable controlled nutrient delivery with reduced dosages; however, their high environmental mobility remains a challenge. This limitation can be overcome by supraparticulate systems formed through the self‐assembly of primary nanoparticles. This study reports the synthesis and characterization of zinc oxide nanoparticles as primary building blocks for supraparticle formation and evaluates their nutrient release kinetics, transport in soil columns, impacts on soil microbial activity, and effects on Panicum miliaceum seedling emergence and Zea mays growth. The ZnO supraparticles (ZnO SPs) were produced by evaporation‐induced self‐assembly on a superhydrophobic surface and characterized using physicochemical analyses. The kinetic profile of zinc release from the SPs showed a slower and sustained release of zinc, with no adverse effects on soil microbial activity. The mobility of the supraparticulate system in the soil column was reduced compared to ZnO nanoparticles and conventional ZnSO 4 , favoring the seedling emergence of Panicum miliaceum . In addition, ZnO SPs enhanced the photosynthetic rate of Zea mays under greenhouse conditions. This study demonstrates the potential of supraparticles as a promising platform for controlled agrochemical release toward sustainable agriculture.